New cpp folder structure

Signed-off-by: Alexander Borsuk <me@alex.bio>

libs/mwm_diff/mwm_diff_tool/mwm_diff_tool.cpp

@@ -0,0 +1,46 @@
+#include "mwm_diff/diff.hpp"
+
+#include "base/cancellable.hpp"
+
+#include <iostream>
+#include <cstring>
+
+int main(int argc, char ** argv)
+{
+  auto const ShowUsage = [argv]()
+  {
+    std::cout <<
+        "Usage: " << argv[0] << " make|apply olderMWMPath newerMWMPath diffPath\n"
+        "make\n"
+        "  Creates the diff between newer and older MWMs at `diffPath`\n"
+        "apply\n"
+        "  Applies the diff at `diffPath` to the mwm at `olderMWMPath` and stores result at `newerMWMPath`.\n"
+        "WARNING: THERE IS NO MWM VALIDITY CHECK!\n";
+  };
+
+  if (argc < 5)
+  {
+    ShowUsage();
+    return -1;
+  }
+
+  auto const IsEqualUsage = [argv](char const * s) { return 0 == std::strcmp(argv[1], s); };
+  char const * olderMWMPath{argv[2]}, * newerMWMPath{argv[3]}, * diffPath{argv[4]};
+
+  if (IsEqualUsage("make"))
+  {
+    if (generator::mwm_diff::MakeDiff(olderMWMPath, newerMWMPath, diffPath))
+      return 0;
+  }
+  else if (IsEqualUsage("apply"))
+  {
+    base::Cancellable cancellable;
+    auto const res = generator::mwm_diff::ApplyDiff(olderMWMPath, newerMWMPath, diffPath, cancellable);
+    if (res == generator::mwm_diff::DiffApplicationResult::Ok)
+      return 0;
+  }
+  else
+    ShowUsage();
+
+  return -1;  // Failed, Cancelled.
+}